Blake Shelton had a heck of a surprise for fans who attended the Sept. 29 opening of his Ole Red restaurant in Tishomingo, Okla. — unannounced, he brought his girlfriend, Gwen Stefani!

"You guys are in for a treat," he teased the crowd early in his set. He sang the first verse of "Go Ahead and Break My Heart" — his duet with Stefani — alone, but who happened to walk out on stage moments later? None other than Stefani herself.

Understandably surprised, the crowd screamed and hollered with approval. The pair traded verses to finish out the song, with Shelton planting a kiss on his No. 1 lady at the end.

Songs Inspired by Blake and Gwen's Love

"That was Gwen Stefani everybody. Gwen freakin' Stefani on Main Street and Kemp in Tishomingo, Oklahoma. That's freaky," he marveled.

But Stefani wasn't Shelton's only famous friend to visit his hometown for the Ole Red grand opening — RaeLynn, John Conlee, Jeannie Seely and Ronnie Milsap also joined in the celebration.

Shelton and Stefani have not been shy about their relationship. Each singer has been surprising the other's fans on the road over the past year, often getting up on stage to duet with one another. Stefani even has Shelton's face on her sneakers! In September, the lovebirds were out in Beverly Hills as Stefani showed off her Vans with a photo from Shelton’s last album cover If I’m Honest on the top of both shoes.